Journal of Dental Research, Vol 66, 1162-1165, Copyright © 1987 by International & American Associations for Dental Research Online Journals
L-serine enhances the anaerobic lactate metabolism of Veillonella dispar ATCC 17745
E. Hoshino
Under anaerobic conditions, the rate of metabolism of lactate by starved
resting cells of Veillonella dispar ATCC 17745 was very low. Because
pyruvate was metabolized well by the starved cells, oxidation of lactate to
pyruvate, which is the first step of the lactate metabolism, must have been
limited in the cells. In the starved cells, the levels of the metabolic
intermediates, oxalacetate or fumarate, of which reductions to malate or to
succinate could be coupled with lactate oxidation to pyruvate and initiate
lactate metabolism, were quite low, suggesting that these had been reduced
during the starvation steps under strictly anaerobic conditions. Thus, the
starved cells were unable to start the anaerobic lactate metabolism because
of shortage of such reducible substrates. L-serine greatly enhanced
anaerobic lactate metabolism of the starved cells. This enhancement may
have been due to metabolism of L-serine itself and conversion to
oxalacetate and fumarate, which made it possible to begin lactate
oxidation.
